Find the gcf of 189 and 200 using prime factorization

Just tell me how to set up the equation.

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?